This invention pertains to a blood sampling device and more particularly to apparatus which reduces the possibility of contamination by diseased blood to the user.
The analysis of the patient's blood is an important diagnostic tool. Blood is drawn from the patient by the use of various syringe-type apparatus. Blood collection devices utilize a needle/cannula inserted into the vein of the patient, i.e. venipuncture, so as to draw the blood through the needle and into an associated collection reservoir. In light of the AIDS problems, attention has been directed to the risk of contamination of the blood drawer/user due to contact with the blood of a diseased patient. Contamination may occur either through the user being punctured by a user needle upon its removal from the blood collection device and/or the splashing of the blood onto the user during such removal.
Various blood collection devices are common in the art. Devices addressing the above problems have also been the subject of prior patents such as those shown in my U.S. Pat. Nos. 4,841,985 and 4,984,580. The basic device generally comprises a needle holder, a needle/cannula assembly and evacuated blood collection tube. The needle assembly, as engaged in the needle holder, presents a front end for puncturing the vein of the patient and a rear end for insertion into an evacuated collection tube contained within the holder. The evacuated tube causes the blood to be drawn from the patient, via the front needle end, and discharged into the collection tube via the rear needle end. As the disposal of the used cannula/needle assembly requires manual handling, the possibility of skin puncture and/or diseased blood splashing onto the user arises after use.
I have invented another needle holder/needle assembly which eliminates the need for the user to manually handle the used needle assembly subsequent to blood purging. An adaptor for a common cannula/needle assembly is inserted into the housing of the holder. The cannula hub is threaded into the adaptor prior to removal of the protective needle cap. The adaptor and cannula threaded therein are held in place by a pair of sliding locks interposed in the housing. Each lock has a slot therein presenting a locking rim. Each rim engages the adaptor so as to maintain the same within the housing. The locking position of the locking rims is maintained by a pair of resilient, bias arms at the front end of each lock which bear against a surface on the opposite lock. The tendency of the bias arms to return to a normal position urges each of the sliding locks into opposed directions and the locking rims into engagement with the housed adaptor. Subsequent to blood withdrawal, the user compresses the sliding locks so as to disengage the locking rims for discharge of the adaptor and associated cannula from the needle holder. The cannula may thus be directed into a waste receptacle for subsequent disposal. Thus, the user need not manually handle the needle assembly subsequent to use.
It is therefor a primary object of this invention to provide for an improved blood collection device which reduces the risk of contamination to users.
Another general object of this invention is to provide for a blood collection device, as aforesaid, which particularly reduces the risk of contamination upon disposal of the utilized needle/cannula assembly.
Still another general object of this invention is to provide for a blood collection device, as aforesaid, which precludes the need for the user to manually handle the needle assembly after use.
Another object of this invention is to provide a blood collection device, as aforesaid, which utilizes a needle assembly releasably engageable with a needle holder.
A further object of this invention is to provide a blood collection device, as aforesaid, which utilizes a bias on the needle assembly to urge removal of the needle assembly from the associated needle holder.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, a now preferred embodiment of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of the elements of the blood drawing system;
FIG. 2 is an exploded view, on an enlarged scale, of the holder, housing and locking assemblies of the blood drawing system with the cannula adaptor displaced therefrom;
FIG. 3 is a side elevation view of the holder prior to insertion of the adaptor therein;
FIG. 4 is a top plan view, taken along line 4--4 in FIG. 3, illustrating the housing assembly and interposed slide locks as presented to the user prior to insertion of the adaptor therein;
FIG. 5 is a top plan view, similar to FIG. 4, with the lid of the housing assembly being removed to show the underlying slide locks of the locking assembly in a normal position with the locking rims of each slide lock subtending the central aperture in the holder;
FIG. 6 is a top plan view, similar to FIGS. 4 and 5, illustrating the slide locks of the locking assembly in a compressed position such that the locking rims of each slide lock are outside the central aperture in the holder;
FIG. 7 is a sectional elevation view, on an enlarged scale and rotated approximately 180.degree. from the FIG. 2 position, illustrating the normal position of the slide locks prior to movement of the adaptor element into the holder housing with the needle assembly displaced therefrom;
FIG. 8 is a sectional elevation view, similar to that of FIG. 7, illustrating the engagement position of the slide locks with the adaptor and the needle within the adaptor;
FIG. 9 is a sectional elevation view, similar to that shown in FIGS. 7 and 8, illustrating the compressed position of the slide locks allowing for release of the slide locks from the adaptor and the needle therein; and
FIG. 10 is a plan view illustrating the underside of the lid of the housing assembly.